Ian Ashdown, P. Eng., FIES, Senior Software Engineer for Lighting Analysts Inc., wrote an interesting whitepaper, Classifying Outdoor Luminaires: The Limits of BUG, available for free download here.
The abstract:
“The IES BUG rating system is useful for classifying outdoor luminaires when considering light trespass, sky glow, and glare in accordance with the Joint IDA-IES Model Lighting Ordinance (MLO). However, there are limits to what can be measured in the laboratory. Luminaires with uplight ratings of U0 or U1 or a glare rating of G0 may require further analysis when comparing manufacturers’ products.”
